how to "corrupt" the binary of a jpeg file?

[pullover]

hello,
i'm from paris and i study graphic design.i'm not familiar with jpeg compression, decoding... i had few searchs on google though.
i would like to learn how to manipulate the binary code of a standard jpeg file for visual, aesthetic, "artitistic " purposes for a new project.
is there any way, program, to read the "heart" of an image and rewrite it to "corrupt" the file, to give it a new aspect? i mean transform it from the inside, no photoshop & co...?
thx

[Frinavale]

A friend of mine took a course on this in university.

It's a lot harder than you think. Unless you have a very strong programming background and you have a concrete understanding about how to manipulate images (there's a lot of math involved) then I would recommend that you stick with using something like Photoshop or gimp :)

-Frinny

[RedSon]

If you don't care about the data, just use a random number generator and insert random values randomly throughout the file. Just make sure you respect the JPG file format (http://en.wikipedia.org/wiki/JPEG) so that you don't corrupt valuable header information or it wont open properly.